BioTechUSA Magnesium Bisglycinate 90 Capsules

Magnesium is one of the few supplements where the form genuinely changes the experience. The cheap oxide forms are poorly absorbed and notoriously hard on the gut, which is why so many people quietly stop taking them.

This one uses magnesium bisglycinate, magnesium chelated to two glycine molecules, and adds vitamin B6. A three-capsule daily dose gives 250mg of magnesium, 67% of the reference intake, alongside 2.0mg of B6 at 143%. Magnesium contributes to a reduction of tiredness and fatigue, to normal muscle function and to the normal functioning of the nervous system; vitamin B6 contributes to normal energy-yielding metabolism.

A bottle holds 90 capsules taken three at a time with a glass of water, so 30 servings is a full month with nothing to measure. The capsule shell is gelatine, so it is not suitable if you avoid animal products, whatever some listings for it claim.